added header to DpiRescaleStyleVisitor

modules/library/main/src/main/java/org/geotools/styling/visitor/DpiRescaleStyleVisitor.java

@@ -1,3 +1,19 @@
+/*
+ *    GeoTools - The Open Source Java GIS Toolkit
+ *    http://geotools.org
+ *
+ *    (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
+ *
+ *    This library is free software; you can redistribute it and/or
+ *    modify it under the terms of the GNU Lesser General Public
+ *    License as published by the Free Software Foundation;
+ *    version 2.1 of the License.
+ *
+ *    This library is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *    Lesser General Public License for more details.
+ */
 package org.geotools.styling.visitor;
 
 import java.util.Map;